Protesters shout slogans during a demonstration against US President Donald Trump’s decision to recognize Jerusalem al-Quds as the “capital” of Israel at the al-Azhar Mosque in Egypt’s capital, Cairo, December 8, 2017. (Photo by AFP)

Clashes have erupted between dozens of protesters and police in the Egyptian capital of Cairo over reports that a young detainee lost his life in custody.

A number of security officials, speaking on the condition of anonymity, said the clashes occurred late on Friday when angry demonstrators allegedly attacked a police station in the capital, torching 10 cars, including three police vehicles.

At least nine people sustained injuries and 40 others were arrested in the overnight violence in Moqattam district, where protesters hurled petrol bombs as police responded by firing tear gas canisters and birdshot, the sources added.

The unnamed officials said the dead detainee was a young man nicknamed Afroto, who had been arrested earlier on Friday for purported drug trafficking but lost his life in a violent brawl, which was sparked between him and other detainees.

The protesters, however, accused the police of being responsible for Afroto’s death. They set fire to tires and nearby vehicles in the vicinity of the police station, leading the fire brigade to intervene.

The clashes, however, fizzled out early on Saturday and calm returned to Moqattam later in the morning after Cairo’s security chief ordered an investigation into the detainee’s death, promising not to obscure any police involvement.

The North African country has tried and sentenced a number of policemen for alleged violent deaths in detention in recent years; with rights groups having repeatedly slammed purported torture and deaths in detention.

Egypt banned all unauthorized protests in 2013 as part of a widespread clampdown on dissent, following the ouster of the country’s first democratically-elected president, Mohamed Morsi, in a military coup.

The country is also suffering from attacks by armed militants in the Sinai Peninsula that have so far killed hundreds of police officers and soldiers.